The earliest reform, which became practically a distinct order, within the Benedictine family. It originated at Cluny, a town in Saone-et-Loire, fifteen miles north-west of Macon, where in 910 William the Pious, Duke of Aquitaine, founded an abbey and endowed it with his entire domain. Over it he placed St. Berno, then Abbot of Gigny, under whose guidance a somewhat new and stricter form of Benedictine life was inaugurated. The reforms introduced at Cluny were in some measure traceable to the influence of St. Benedict of Aniane, who had put forward his new ideas at the first great meeting of the abbots of the order held at Aachen (Aix-la-Chapelle) in 817, and their development at Cluny resulted in many departures from precedent, chief among which was a highly centralized form of government entirely foreign to Benedictine tradition. The reform quickly spread beyond the limits of the Abbey of Cluny, partly by the founding of new houses and partly by the incorporation of those already existing, and as all these remained dependent upon the mother-house, the Congregation of Cluny came into being almost automatically. Under St. Berno's successors it attained a very widespread influence, and by the twelfth century Cluny was at the head of an order consisting of some 314 monasteries. These were spread over France, Italy, the Empire, Lorraine, England, Scotland, and Poland. According to the "Bibliotheca Cluniacensis" (Paris, 1614) 825 houses owed allegiance to the Abbot of Cluny in the fifteenth century. Some writers have given the number as 2000, but there is little doubt that this is an exaggeration. It may perhaps include all those many other monasteries which, though no joining the congregation, adopted either wholly or in part the Cluny constitutions, such as Fleury, Hirschau, Farfa, and many others that were subject to their influence.

During the first 250 years of its existence Cluny was governed by a series of remarkable abbots, men who have left their mark upon the history of Western Europe and who were prominently concerned with all the great political questions of their day. Among these were Sts. Odo, Mayeul, Odilo, and Hugh, and Peter the Venerable. Under the last named, the ninth abbot, who ruled from 1122 to 1156, Cluny reached the zenith of its influence and prosperity, at which time it was second only to Rome as the chief centre of the Christian world. It became a home of learning and a training school for popes, four of whom, Gregory VII (Hildebrand), Urban II, Paschal II, and Urban V, were called from its cloisters to rule the Universal Church. In England the Cluniac houses numbered thirty-five at the time of the dissolution. There were three in Scotland. The earliest foundation was that of the priory of St. Pancras at Lewes (1077), the prior of which usually held the position of vicar-general of the Abbot of Cluny for England and Scotland. Other important English houses were at Castleacre, Montacute, Northampton, and Bermondsey.

After the twelfth century the power of Cluny declined somewhat, and in the sixteenth century it suffered much through the civil and religious wars of France and their consequences. The introduction also of commendatory abbots, the first of whom was appointed in 1528, was to some extent responsible for its decline. Amongst the greatest of its titular prelates were Cardinals Richelieu and Mazarin, who tried to restore it to some of its former greatness, though their efforts did not meet with much success. Claude de Vert, Prior of Saint-Pierre, Abbeville (d. 1708), was another would-be reformer of the congregation, inspired no doubt by the example of the Maurists.

The abbey-church of Cluny was on a scale commensurate with the greatness of the congregation, and was regarded as one of the wonders of the Middle Ages. It was no less than 555 feet in length, and was the largest church in Christendom until the erection of St. Peter's at Rome. It consisted of five naves, a narthex, or ante-church, and several towers. Commenced by St. Hugh, the sixth abbot, in 1089, it was finished and consecrated by Pope Innocent II in 1131-32, the narthex being added in 1220. Together with the conventual buildings it covered an area of twenty-five acres. At the suppression in 1790 it was bought by the town and almost entirely destroyed. At the present day only one tower and part of a transept remain, whilst a road traverses the site of the nave. The community of the abbey, which had numbered three hundred in the thirteenth century, dwindled down to one hundred in the seventeenth, and when it was suppressed, in common with all the other religious houses in France, its monks numbered only forty.

The spirit and organization of the congregation was a distinct departure from the Benedictine tradition, though its monks continued all along to be recognized as members of the Benedictine family. Previous to its inception every monastery had been independent and autonomous, though the observance of the same rule in all constituted a bond of union; but when Cluny began to throw out offshoots and to draw other houses under its influence, each such house, instead of forming a separate family, was retained in absolute dependence upon the central abbey. The superiors of such houses, which were usually priories, were subject to the Abbot of Cluny and were his nominees, not the elect of their own communities, as is the normal Benedictine custom. Every profession, even in the most distant monastery of the congregation, required his sanction, and every monk had to pass some years at Cluny itself. Such a system cut at the root of the old family ideal and resulted in a kind of feudal hierarchy consisting of one great central monastery and a number of dependencies spread over many lands. The Abbot of Cluny or his representative made annual visitations of the dependent houses, and he had for his assistant in the government of so vast an organization a coadjutor with the title Grand-Prior of Cluny. The abbot's monarchical status was somewhat curtailed after the twelfth century by the holding of general chapters, but it is evident that he possessed a very real power over the whole congregation, so long as he held in his own hands the appointment of all the dependent priors. (For the sources of information as to the rule, government, and conventual observance of the congregation, see bibliography at end of this article.) With regard to the Divine Office, the monks of Cluny conformed to the then prevailing custom, introduced into the monasteries of France by St. Benedict of Aniane, of adding numerous extra devotional exercises, in the shape of psalms (psalmi familiares, speciales, prostrati, and pro tribulatione) and votive offices (Our Lady, The Dead, All Saints, etc.) to the daily canonical hours prescribed by the Benedictine Rule.

The library of Cluny was for many centuries one of the richest and most important in France and the storehouse of a vast number of most valuable MSS. When the abbey was sacked by the Huguenots, in 1562, many of these priceless treasures perished and others were dispersed. Of those that were left at Cluny, some were burned by the revolutionary mob at the time of the suppression in 1790, and others stored away in the Cluny town hall. These latter, as well as others that passed into private hands, have been gradually recovered by the French Government and are now in the Bibliotheque Nationale at Paris. There are also in the British Museum, London, about sixty charters which formerly belonged to Cluny. The "Hotel de Cluny" in Paris, dating from 1334, was formerly the town house of the abbots. In 1833 it was made into a public museum, but apart from the name thus derived, it possesses practically nothing connected with the abbey.

For the rule, constitutions, etc., see BERNARD OF CLUNY, Ordo Cluniacensis in HERRGOTT, Vetus Disciplina Monastica (Paris, 1794); and UDALRIC OF CLUNY, Consuetudines Cluniacensis in P.L., CXLIX (Paris, 1882). For the history of the congregation, etc., DUCKET, Charters and Records of Cluni (Lewes, 1890); MAITLAND, Dark Ages (London, 1845); MABILLON, Annales O. S. B. (Paris, 1703-39), III-V; SAINTE-MARTHE, Gallia Christiana (Paris, 1728), IV, 1117; HELYOT, Hist. des ordres religieux (Paris, 1792), V; MIGNE, Dict. des abbayes (Paris, 1856); LAVISSE, Hist. de France (Paris, 1901), II, 2; LORAIN, Hist. de l'abbaye de Cluny (Paris, 1845); CHAMPLY, Hist. de Cluny (Macon, 1866); HEIMBUCHER, Die Orden und Kongregationen der katholischen Kirche (Paderborn, 1896), I; HERZOG AND HAUCK, Realencyklopadie (Leipzig, 1898), III; SACKUR, Die Cluniacenser (Halle a. S., 1892-94).

G. CYPRIAN ALSTON